title: Ribosomal scanning on the 5'-untranslated region of the human immunodeficiency virus RNA genome.
abstract: Translation initiation on most eukaryotic mRNAs occurs via a cap-dependent scanning mechanism and its efficiency is modulated by their 5'-untranslated regions (5'-UTR). The human immunodeficiency virus type 1 (HIV-1) 5'-UTR contains a stable TAR hairpin directly at its 5'-end, which possibly masks the cap structure. In addition, the 5'-UTR is relatively long and contains several stable RNA structures that are essential for viral replication. These characteristics may interfere with ribosomal scanning and suggest that translation is initiated via internal entry of ribosomes. Literature on the HIV-1 5'-UTR-driven translation initiation mechanism is controversial. Both scanning and internal initiation have been shown to occur in various experimental systems. To gain further insight in the translation initiation process, we determined which part of the 5'-UTR is scanned. To do so, we introduced upstream AUGs at various positions across the 5'-UTR and determined the effect on expression of a downstream reporter gene that was placed under control of the gag start codon. This strategy allowed us to determine the window of ribosomal scanning on the HIV-1 5'-UTR.
authors.affiliation: Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam, Academic Medical Centre, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Ben
authors.initials: B
authors.lastname: Berkhout
authors.forename: Kelly
authors.initials: K
authors.lastname: Arts
authors.forename: Truus E M
authors.initials: TE
authors.lastname: Abbink
mesh_terms: D020121:5' Untranslated Regions; D001483:Base Sequence; D045744:Cell Line, Tumor; D018387:Codon, Initiator; D016679:Genome, Viral; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010442:Peptide Chain Initiation, Translational; D012367:RNA, Viral / Q000737:chemistry*; D012270:Ribosomes / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000096:biosynthesis / Q000235:genetics
chemical_list: D020121:5' Untranslated Regions; D018387:Codon, Initiator; D012367:RNA, Viral; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus